1. Field of the Invention
The present invention is generally directed toward internal combustion engines and, more specifically, to an internal combustion engine having an improved structural oil pan.
2. Description of the Related Art
Internal combustion engines known in the related art typically include, among other basic components, a cast engine block, a head mounted to the engine block and a valve cover fastened to the head. A plurality of pistons are reciprocated in cylinders formed in the engine block. Similarly, a plurality of valves supported in the head are opened and closed via rocker arms, cams or some other mechanism to provide fluid communication between the cylinders and intake and exhaust manifolds. Fuel is combusted within the cylinders to reciprocate the pistons which, in turn, act on a crankshaft from which power may be translated to drive an automotive vehicle or any number of other devices.
The various moving parts in an internal combustion engine need to be lubricated and cooled. To this end, coolant is circulated through the engine block and lubricant, such as engine oil, is splashed over the moving parts. Thereafter, the lubricant moves through the engine under the force of gravity and is collected in an oil pan that is fixed to the underside of the engine block. The lubricant is pumped from the oil pan up into the head and engine block via pick up tubes communicating with the oil pan. The lubricant must also be filtered and cooled and most engines employ separate oil filters and coolers which are plumbed into the lubrication circuit via various tubes and housings supported by brackets and seals associated with the engine.
Modern internal combustion engines often typically require engineered components to limit noise and vibrations. This is especially true of diesel engines, some of which require a high degree of noise and vibration attenuation to remain competitive in certain markets. The engine oil pan is a significant noise radiation source in a diesel engine. To limit the noise radiation from this source, special materials or composites may be employed for the oil pan which dampen engine noise. Alternatively, the oil pan may be stiffened or weakened to shift the natural vibration frequencies for the oil pan outside the excitation frequency range for the engine. In this way, the noise from the oil pan may be minimized.
However, in some engines, especially heavy duty applications, the oil pan serves as a structural member for the engine and associated transmission. In such situations, the oil pan must be stiffened, rather than weakened. Further, in these cases, most noise dampening materials and composites are not practical for such applications.
Thus, there is a need in the art for improved noise and vibration attenuation for internal combustion engines and especially such attenuation through the oil pan on diesel engines. In addition to noise and vibration attenuation, there is a constant need to simplify systems and reduce components to reduce costs and streamline the manufacturing process for internal combustion engines.